Time to begin the turf wars

Drought, disease and dead grass. It's the plot of a horticultural horror film, and you're wondering whether it's going to end as badly as it began.

Never in the history of North Texas lawn-keeping have there been so many people with so many problems. How do you sort through the crisis, so you can cope with the ones that are most pressing? I have some help, so you may have hope.

Start with the weeds. Mowing will get rid of many, plus it will reduce the humiliation factor. You may have to mow more often than you normally do, but such is the price of a well-groomed estate. Despite your efforts, some weeds will persist, so you'll have to go to Plans B and C.

Broadleaf weeds (including dandelions, clover, dichondra, the less-common dollar weed) can be eliminated with an application of a broadleaf weed killer. Most contain 2,4-D, which alone does not work through the soil, but the other active ingredients may, and that's why you'll see warnings not to use them beneath trees. There are products that contain only 2,4-D. Your local nurseryman will be most likely to have them. It's best to use a pump sprayer, not a hose-end type to apply them. Pumps apply less active ingredient, and they do so more uniformly. Once you use a sprayer for broadleaf weeds, don't use it for insecticides or fungicides. It's difficult to rinse out the residue.

Weed grasses such as rye grass, rescue grass and annual bluegrass (Poa annua) are finishing up their winter growing cycles. No weed killer can eliminate unwanted grasses without damaging your lawn. To prevent the same problem from happening this time next year, apply pre-emergent weed-killer granules the first week of September. This year's crop will die out as it turns warmer in late April and May.

You're also seeing the new growth of a couple of difficult perennial grassy weeds. Dallis grass establishes very heavy, dinner-plate-sized clumps of dark green blades. During the late spring and summer, dallis grass flowers and forms seeds within days of each mowing. Your only option is to dig it up by hand. Use a sharpshooter spade when the soil is moist.

Nutsedge is appearing now, sprouting up from the pea-sized brown storage roots that look like tiny coconuts. You can always confirm its identification by rolling its stem between your thumb and index finger. Nutsedge stems are triangular. True grasses have round stems. Nutsedge is our most tenacious weed, and only dedicated nutsedge controls such as the original Image or Sedgehammer will make significant inroads into its population. Treatment time begins in May and runs through the end of the summer.

Once you've made your first pass at controlling the weeds, it's time to fertilize your turf. Soil tests from the Blackland Prairie almost always come back showing a need for only nitrogen. Most clay soils test too high in phosphorus, the middle number of the fertilizer analysis. Your fertilizer should have half or more of its nitrogen in timed-release, encapsulated form to ensure extended feeding. Repeat the application early June, early August and early October for Bermuda turf, and early June and early September for St. Augustine. Follow your feeding with a thorough watering, but don't try to anticipate rainfall by fertilizing at the time soaking rains are expected. There is too much chance of runoff before the nutrients can dissolve and soak into the soil.

Keep mowing your lawn at the recommended height the balance of the spring and summer. By keeping Bermuda or St. Augustine toward the low end of the recommended range, you'll encourage dense and spreading growth. Tall grass soon becomes weak grass. Mow low, and mow often. Common Bermuda should be cut at 11/4 to 11/2 inches, and St. Augustine at 2 to 21/2 inches. Try never to remove more than one-third of the leaf blades at each mowing. That translates to every five or six days by late spring and summer.

Fill voids in your lawn with exactly the same type and variety of grass that you already have. The best way is to dig plugs from your turf and checkerboard them into the bald areas. Bermuda varieties, for example, vary a great deal in appearance, and you don't want to get them mixed in the same lawn. However, if you're absolutely sure of the type, you can certainly buy sod and cut it into 8-inch squares, then plant them on 24-inch centers. It is difficult to get Bermuda seed to take root and grow within a lawn. Planting plugs is a much easier way to repair areas up to 10 or 15 feet across. Prime time for planting seed or sod in North Texas is mid-April through mid-June (sooner if it turns hot early).

One final precaution: if the dead areas in your turf coincide with the shade beneath trees, your loss of grass may be due solely to shade, not to the drought. Planting grass in that case would be a wasted effort.

Neil Sperry publishes Gardens magazine and hosts Texas Gardening 8-11 a.m. Sundays on WBAP AM/FM. Reach him during those hours at 800-288-9227 or 214-787-1820